Jaafar Hallal^1,*, Mahmoud Fakih², Hala Damerji³, Mohammad Hammoud^4,5, Mehdi Chouman^4,5

Sound & Vibration, Vol.55, No.2, pp. 131-140, 2021, DOI:10.32604/sv.2021.015293

Abstract Vibration can be introduced in all mechanical fields in our life. Engineers try to avoid its negative effect leading in some cases to deformation in the machines. Many researches are dedicated to study the identification of damping especially in multi degree of freedom systems with particular attention to the source of energy dissipation. They focus on developing new tools or methods which may be used in real problems to obtain accurate results about the amount (or value) and the location of energy dissipation in the structure. The aim of this paper is to present an original procedure aims to experimentally… More >

Motoharu Fujigaki^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 26-26, 2021, DOI:10.32604/icces.2021.08385

Abstract Several types of accurate and high-speed 3D shape measurement using linear LED devices were developed by author's research group. The linear LED device is a key device to develop them. High-speed phase shift synchronized with camera triggers can be achieved by switching the lighting position of the linear LED. The control signals can be generated easily with a no special micro-computer. A compact projector unit can be produced. Author also proposed a calibration method, named a whole-space tabulation method (WSTM), for an accurate and high-speed shape measurement using multiple reference planes. A handy, fullcolor and real-time 3D shape measurement unit… More >

Ayumi Takahashi^1,*, Tomoyuki Tsuchiya², Keiichi Motoyama³, Kazuhito Misaji¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 15-15, 2021, DOI:10.32604/icces.2021.08354

Abstract The seismic-isolation laminated rubber is used as a means of suppressing damage to the structures caused by an earthquake. To design the seismically isolated structure, it is important to calculate the dynamic response reflecting the rubbers characteristics accurately. The authors have applied the nonlinear vibration analysis method using the restoring force model of the power function type to the seismic response analysis of seismic isolation rubber in horizontal unidirectional [1-3]. However, when seismic isolation laminated rubber is loaded in horizontal bi-direction, the seismic isolation laminated rubber is torsional deformed and breaks with less force than when loaded in unidirectional. It… More >

Shichao Ma^{1, 2}, Xin Ning^{1, 2}, Pengbi Cui^{1, 2}, Lili Ren^{1, 2}, Liang Wang³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 7-8, 2021, DOI:10.32604/icces.2021.08233

Abstract Vibration isolation design is essential for the spacecraft capture operation in the on-orbit servicing missions. And contact impact is also inevitable in this process, which can be simplified as piece-smooth ordinary differential equations and generate abundant dynamics phenomena. Therefore, it is especially important to study the contact dynamics responses. And global behavior research can be visualized the characteristics of system. Aiming to this issue, the global dynamics of a single-degree-of-freedom non-smooth mechanical system in a vibration isolation experiment is studied by using advanced numerical procedure in this paper. For this non- smooth impact and friction oscillator, the forcing frequency is… More >

Sami Allagui^1,2,*, Abderrahim El Mahi¹, Jean-Luc Rebiere¹, Moez Beyaoui², Anas Bouguecha², Mohamed Haddar²

Journal of Renewable Materials, Vol.9, No.4, pp. 695-721, 2021, DOI:10.32604/jrm.2021.013586

Abstract This manuscript deals with the effects of recycling on the static and dynamic properties of flax fibers reinforced thermoplastic composites. The corresponding thermoplastic used in this work is Elium resin. It’s the first liquid thermoplastic resin that allows the production of recycled composite parts with promising mechanical behavior. It appeared on the resin market in 2014. But until now, no studies were available concerning how it can be recycled and reused. For this study, a thermocompression recycling process was investigated and applied to Elium resin. Flax fiber-reinforced Elium composites were produced using a resin infusion process and were subjected to… More >

Zilu Meng¹, Zhehan Hu¹, Zhenzhen Ai¹, Yanan Zhang^2,*, Kunling Shan²

Journal on Big Data, Vol.3, No.1, pp. 11-20, 2021, DOI:10.32604/jbd.2021.015208

Abstract Establishing the Lagrangian equation of double complex pendulum system and obtaining the dynamic differential equation, we can analyze the motion law of double compound pendulum with application of the numerical simulation of RK-8 algorithm. When the double compound pendulum swings at a small angle, the Lagrangian equation can be simplified and the normal solution of the system can be solved. And we can walk further on the relationship between normal frequency and swing frequency of double pendulum. When the external force of normal frequency is applied to the double compound pendulum, the forced vibration of the double compound pendulum will… More >

H. Heydarnia^1,*, I. A. Kiselev¹, M. M. Ermolaev², S. Nikolaev³

Sound & Vibration, Vol.55, No.1, pp. 19-30, 2021, DOI:10.32604/sv.2021.04410

Abstract Studying the vibrational behavior of feed drive systems is important for enhancing the structural performance of computer numerical control (CNC) machines. The preload on the screw and nut position have a great influence on the vibration characteristics of the feed drive as two very important operational conditions. Rotational acceleration of the screw also affects the performance of the CNC feed drive when machining small parts. This paper investigates the influence of preload and nut position on the vibration characteristics of the feed drive system of a CNC metal cutting machine in order to be able to eliminate an observed resonance… More >

Ehsan Noroozinejad Farsangi^1,*, Aleksandra Bogdanovic², Zoran Rakicevic², Angela Poposka², Marta Stojmanovska²

Structural Durability & Health Monitoring, Vol.14, No.4, pp. 283-301, 2020, DOI:10.32604/sdhm.2020.010564

Abstract In this study, the methodology and results of ambient vibration-based investigations of the historical Tash Mosque in Kosovo and a 3-story historical building in Bulgaria are presented. The investigations include full-scale in situ testing of both structures due to ambient vibrations induced by micro-seismic, wind, traffic, and other human activities. To this aim, Ranger seismometers and Kinemetric products were used. Measurements were performed in both horizontal directions in several points along the structures’ height utilizing a high-speed data acquisition device. All recorded data have been analyzed and processed by the software developed at IZIIS, and then the processed data were… More >

Jaafar Hallal^1,2,3,*, Mohammad Hammoud^2,3, Mahmoud Fakih^2,3,4, Ali Hallal^2,3

Sound & Vibration, Vol.54, No.4, pp. 225-236, 2020, DOI:10.32604/sv.2020.011513

Abstract The vibrations behavior analysis is an essential step in the mechanical design process. Several methods such as analytical modelling, numerical analysis and experimental measurements can be used for this purpose. However, the numerical or analytical models should be validated through experimental measurements, usually expensive. This paper introduces an inexpensive smartphone as an accurate, non-intrusive vibrations’ behavior measurement device. An experimental measurement procedure based on the video processing method is presented. This procedure allows the measurement of the natural frequencies and the mode shapes of a vibrating structure, simply by using a smartphone built-in camera. The experimental results are compared to… More >

Zhiyuan Liu^1,2, Xin Tan², Xiaobo Liu^1,2, Pingan Chen^1,2, Ke Yi^1,2, Tianzhi Yang^1,2, Qiao Ni^3,4, Lin Wang^3,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.125, No.2, pp. 495-514, 2020, DOI:10.32604/cmes.2020.012030

Abstract Cantilevered pipe conveying fluid may become unstable and flutter instability would occur when the velocity of the fluid flow in the pipe exceeds a critical value. In the present study, the theoretical model of a cantilevered fluid-conveying pipe attached by an inerter-based dynamic vibration absorber (IDVA) is proposed and the stability of this dynamical system is explored. Based on linear governing equations of the pipe and the IDVA, the effects of damping coefficient, weight, inerter, location and spring stiffness of the IDVA on the critical flow velocities of the pipe system is examined. It is shown that the stability of… More >